Circuits and devices operated with DC voltage can be damaged by interchanging the supply lines. The same applies to devices operated with AC voltage, which can be damaged by reversing the neutral conductor and the protective conductor.
To prevent damage caused by reversing the polarity of the supply voltage, electronic reverse polarity protection is available. Such reverse polarity protection ensures that no damage is caused to the equipment if the supply leads are reversed, and also that the operator cannot receive an electric shock.
The electronic reverse polarity protection for devices supplied with DC voltage consists of a simple diode or Zener diode circuit that blocks or diverts incorrectly applied voltages. This purpose is also served by an electronic fuse, e-Fuse, which protects against inrush currents and reverse polarity in addition to overvoltages.